Hydrocarbon tin alcoholates



Patented Jan. 22, 1952 HYDROCARBON TIN ALCOHOLATES Samuel L. Burt,Plainfield, N. J assignor, by mesne assignments, to Union Carbide andCarbon Corporation, a corporation of New York No Drawing. ApplicationDecember 15, 1948, Serial No. 65,521

"3 Claims. (01. 2so 429 This invention provides an improved method formaking the hydrocarbon tin alcoholates.

Hydrocarbon tin alcoholates may be made at present by an expensiveprocess involving the reaction of a dialkyl tin dibromide with a sodiumalcoholate. I have discovered a cheaper and more effective process.According to this invention, hydrocarbon tin alcoholates are prepared byreacting a dialkyl r diaryl tin oxide directly with an alcohol. In thisprocess, there is no consumption of expensive reagents, as occurs in theprevious process, whereinv two moles of bromine and two moles of sodiumare consumed for each mole of tin alcoholate formed. The reaction whichoccurs in the process of the invention may be represented for monohydricalcohols as follows:

where R is an alkyl radical, such as a methyl, ethyl, isopropyl, butyl,2-ethylbutyl or 2-ethylhexyl radical, or an aryl radical, such as aphenyl or toluyl radical and R1 is the residue of an alcohol.

The reaction of the present invention is a general one, and by means ofthis reaction it is possible to prepare hydrocarbon tin alcoholates of anumber of alcohols, which are diflicult if not impossible to prepare bythe prior art method. Thus, it is possible to prepare hydrocarbon tinalcoholates of polyhydric alcohols by this new method. The reactionwhich occurs between the hydrocarbon tin oxide and polyhydric alcoholsmay be represented as follows:

moval of the water of reaction is facilitated by carrying out thereaction in the presence of a water-immiscible organic diluent, such asa hydrocarbon or an ether, and refluxing the contents of the flask toremove the water and the diluent as a distillate. If desired, the watermay be decanted from the fcondensed distillate and the organic diluentwhich separates returned to the reaction vessel.

The following examples will illustrate the invention:

Example 1 One mole (249 grams) of anhydrous dibutyl tin oxide was mixedwith one mole (62 grams) of ethylene glycol and 300 milliliters ofmethyl cyclohexane in one-liter round bottom, Pyrex flask having threenecks. The flask was provided with a mechanical agitator and refluxcondenser.

Heat was applied to the flask and the contents brought to the boilingpoint. At the time reflux had started, the contents Of the flask becamehomogeneous. After heating for two hours under reflux, the contents ofthe flask were cooled to about C. and then transferred to a oneliter,Pyrex autoclave. The autoclave was evacuated to about 50 millimeters ofmercury, absolute pressure, and was heated by means of a boiling waterbath until only a solid residue remained. This solid was removed fromthe autoclave, crushed to a powder and residual solvent removed byheating the solid in a vacuum oven at to C. and 2 to 5 millimeters ofmercury pressure, absolute, for a period of two hours. The product,(C4H9)2SI1(OC2H4O), melted at to 200 0.

Examples 2 to 8 By a procedure similar to that of Example 1, the dibutyltin alcoholates of the following alcohols were prepared, using for eachmole of dibutyl tin oxide 2/:1: moles of alcohol, a: being the number ofhydroxyl groups per. molecule of the alcohol. The alcohol used in eachpreparation, and certain properties of the tin alcoholates found arelisted below:

Example No.

holate allyl alcohol butyl alcohol; diethylene glycoL.

- iurfuryl alcohol.

All of these alcoholates are useful as heat stabilizers for vinylchloride resins, but of them the dibutyl tin alcoholates of furfurylalcohol and benzyl alcohol are outstanding, as described 55 in mycopending application, Serial No. 65,522,

entitled "Stabilized Vinyl Chloride Resins." now ing water from thereaction zone during said Patent No. 2,489,518. heating, and recoveringa hydrocarbon tin alco- What is claimed is: holate of said alcohol.

1. A dibutyl tin alooholate of an aliphatic SAMUEL L. BURT. polyhydricprimary alcohol containing from 2 to 5 5 carbon atomsand from 2 to 4hydroxyl groups. REFERENCES CITED The dibtuyltin alcoholate fethyleneglycol- The following references are of record in the 3. Processfor 'making a dialkyl tin alcoholate file of t patent: which comprisesheating a. dialkyl tin oxide with Harada, Sci. Papers Inst. Phy. andChem. Rean aliphatic f mlyhydm search (Tokyo) vol. 35 (1939), page 304.

1. A DIBUTYL TIN ALCOHOLATE OF AN ALIPHATIC POLYHYDRIC PRIMARY ALCOHOLCONTAINING FROM 2 TO 5 CARBON ATOMS AND FROM 2 TO 4 HYDROXYL GROUPS.